Currently we do not have formal testing for deb package format. I am not sure if it is OK to enable it on autobuilder. Just open a bug here.
I can open it on the AB however doing so would impact build times. If we plan on having deb testing, I'm more than happy to enable it.
http://git.yoctoproject.org/cgit/cgit.cgi/yocto-autobuilder/commit/?id=33c8675768cc04638c5dd063fe97e7f7f1cc0a04
Verified http://autobuilder.yoctoproject.org/pub/nightly/20120809-1/deb/qemuppc/